His thoughts unfurled like the miles, and he was relaxed and happy, despite his session with the doctor. His sense of freedom was at one with the cloudless sky, blueish-black at the zenith, and the empty landscape before him. Here was the culmination of eight years' work. Travelling to Lordsburg was every Englishman's ideal of America – the open road narrowing to the horizon, the colossal space, the possibilities. Along the route, especially on the southern side, projecting from the tops of sandy banks and hillocks, were piles of stones, some of them five feet high, one stone balanced on another to give a vaguely humanoid aspect. They had a primitive, ancient look, and when he had first seen them he had assumed they were Aztec relics, the local equivalent of menhirs and dolmens. But they were marks of triumph left by Mexican immigrants who had crossed the border and tramped the miles of scrub to rendezvous with their connections. At intervals by the road were Border Patrol observation stations. Elsewhere they parked their pick-ups on strategic rises and watched through binoculars the grey-green expanse of arid ranchland. Who could blame the immigrants? Who would not want to come to a place where a foreigner could be welcomed to launch a revolutionary energy plant with generous local help and tax breaks, and army marching bands and air-force fly-pasts? It would not have been so smooth in Libya or Egypt.

Hammer interrupted the pleasant inward drift of his thoughts. 'There's a message from a lawyer in Albuquerque, been trying to get in touch with you. Says he represents an Englishman called Braby. Wants to talk to you about something in connection with his client.'

'He wrote to me last week, wanting a meeting,' Beard said. 'Ignore it. I don't owe Braby any favours. He's the one who got me sacked from the Centre in England. Remember I told you that story.'

Hammer straightened up and slumped back against the headrest. 'Looking at this screen is making me sick.' He spoke with eyes closed. 'The lawyer's name is Barnard, and he's flying down here tomorrow. He needs to talk to you. You sure there's nothing wrong, something I should know about?'

'Braby's just the sort to kick you in the face, then ask a favour. Ignore it.'

Hammer kept his eyes shut and said nothing for a minute, and Beard thought he had fallen asleep until he said, 'When a lawyer comes some distance unasked to meet you, travelling at his client's expense, you expect trouble.'

Beard let this go. What was there to argue about? He had been ignoring Braby for years. Let him do the brave thing, and pick up the phone himself. It was not difficult to guess his business. An introduction to the NREL in Golden, access to venture capital for the Centre, or maybe the inside line on solar or on tax breaks. Why worry?

They passed through Columbus, and as the Cedar Mountains rose into view they had one more desultory conversation about their iron-filing scheme. Everything was in place, the investors, the captain, the ship, an option to purchase the filings. All that was missing now was a carbon-trading scheme.

'We've got Obama working on it,' Hammer said. 'We can think about other things, but when it comes, we'll be ready.'

The instrument panel was showing an external temperature of one hundred and twelve degrees Fahrenheit, hotter than either man had ever known. Beard pulled over so they could experience the full blast. It was a mistake perhaps, to go hatless straight from the refrigerated cabin into such savage heat, or perhaps it was his sudden exertion after ninety minutes behind the wheel. As he stepped onto the edge of the road, just as he was about to exclaim to his friend something banal, he felt dizzy, his consciousness partially faded and his knees gave way. If he had not kept hold of the car door handle, he would have dropped to the ground. As it was, he swayed and half stumbled, but managed to stay on his feet as his shoulder swung back hard against the car. His pulse was racing as he struggled with the rear door to look for his hat. He leaned into the relative cool of the back seat and fumbled with his panama and, resting there a few seconds, began to feel better. The episode had taken less than fifteen seconds. Hammer, who was on the other side of the car, saw nothing.

The two men stepped away from the road, marvelling. The heat created a form of synaesthesia. It was loud, vulgar, it towered over them, its weight pressed down on their heads, and it leaped up from the ground and struck their faces. Who would believe that a photon had no mass?

'Here it is,' Beard cried, miming triumph with a raised clenched fist to disguise his strange turn and reassure himself with the sound of his own voice that he was still the same man. 'This is the power!'

'All power to the power!' Hammer said. 'But I've had enough.'

Hammer got back in the car, behind the wheel, and that was a relief, Beard thought as he climbed in beside him. He was still too shaky to drive. Now they were travelling close to eighty and in less than half an hour were through Hachita and Playas, then crossing the Continental Divide below the Pyramid Mountains, in Hidalgo County, in the boot heel of the state. Their site was barely an hour away, on the far side of Lordsburg, and as they got nearer they became noisy and jaunty, more like country boys on their way to a hoedown than men in their sixties with awesome responsibilities. They sang 'The Yellow Rose of Texas', the nearest to a cheerful song about New Mexico that they knew. The way had been long and hard, they had travelled together uncomfortably, sometimes miserably in the Middle East, and tiringly through the American South-West. The lab work and the office work had driven them apart at times, and now, finally, they were about to share their secret, the ancient secret of plants, and astound the world with their version of cheap, clean and continuous energy. For old times' sake, and because it was their favourite spot, they turned south at the Animas junction and pulled into the dusty parking lot of the Panther Tracks café and parked right beside the local sheriff's patrol car.

Hammer had mythologised Animas as the friendliest rural community in the States. The day it acquired sidewalks, he said, he would stop coming. The caf̩ Рthe finest west of the Mississippi Рwas a white painted shed with few windows. Stepping out of the heat of the early afternoon, they paused in the doorway to let their eyes adjust. The sheriff and another cop were in quiet conference over mugs of coffee and were the only customers. In the Panther Tracks you did not order what you wanted, but what was available. Today it was pancakes and bacon. The coffee was the specially weak brew favoured across the American South. While they waited, Beard took out his palmtop. It had absorbed new messages that morning in the hotel, but he had not yet opened them. What caught his attention straight off was the name of P. Banner, his fifth ex-wife, Patrice, now married to a cosmetic dentist, Charles, who doted on her almost as much as Beard had nine years ago. She was briefly a headmistress before producing three babies in four years. And all those times she had told Beard that she never wanted children. Not his, anyway. Interesting, that Charles was short, plump and had even less hair than Beard and was two years older. As if marriages were a series of corrected drafts.

A year ago he had bumped into her in Regent's Park with her son, a delicate five-year-old with girlish curls. She was friendly, and he thought she was still beautiful. They sat on a bench and chatted for fifteen minutes. By devious means, Beard managed to pose the one question on his mind. Was she still an unfaithful wife? Yes, she might be, was her equally devious implication, but he did not stand a chance, if that was what he meant.

Dear Michael, This might not be news to you, but in case it is you should know that five weeks ago, Rodney came out of prison. He tried to get in touch with me. He has all sorts of mad ideas I won't begin to describe. Charles's lawyer went to court and got a prohibitive-steps order that means he'll be arrested if he phones or writes or comes within 500 yards of our house. Now I've just heard from friends of friends that he's gone to the States to look for you. Perhaps he wants to thank you personally for giving evidence against him at his trial! Anyway, I think you should be warned. It's half-term tomorrow and we are all off to the Shetlands in the pouring rain. All best, Patrice.